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-rw-r--r--arch/x86/kernel/kprobes.c42
-rw-r--r--kernel/kprobes.c3
2 files changed, 29 insertions, 16 deletions
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index f49f60cca40d..b7c2a85d1926 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -541,6 +541,8 @@ reenter_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb
return 1;
}
+static void __kprobes skip_singlestep(struct kprobe *p, struct pt_regs *regs,
+ struct kprobe_ctlblk *kcb);
/*
* Interrupts are disabled on entry as trap3 is an interrupt gate and they
* remain disabled throughout this function.
@@ -599,6 +601,12 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
} else if (kprobe_running()) {
p = __this_cpu_read(current_kprobe);
if (p->break_handler && p->break_handler(p, regs)) {
+#ifdef KPROBES_CAN_USE_FTRACE
+ if (kprobe_ftrace(p)) {
+ skip_singlestep(p, regs, kcb);
+ return 1;
+ }
+#endif
setup_singlestep(p, regs, kcb, 0);
return 1;
}
@@ -1053,6 +1061,21 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
}
#ifdef KPROBES_CAN_USE_FTRACE
+static void __kprobes skip_singlestep(struct kprobe *p, struct pt_regs *regs,
+ struct kprobe_ctlblk *kcb)
+{
+ /*
+ * Emulate singlestep (and also recover regs->ip)
+ * as if there is a 5byte nop
+ */
+ regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;
+ if (unlikely(p->post_handler)) {
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ p->post_handler(p, regs, 0);
+ }
+ __this_cpu_write(current_kprobe, NULL);
+}
+
/* Ftrace callback handler for kprobes */
void __kprobes kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct pt_regs *regs)
@@ -1077,19 +1100,12 @@ void __kprobes kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
__this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
- if (p->pre_handler)
- p->pre_handler(p, regs);
-
- if (unlikely(p->post_handler)) {
- /*
- * Emulate singlestep (and also recover regs->ip)
- * as if there is a 5byte nop
- */
- regs->ip = ip + MCOUNT_INSN_SIZE;
- kcb->kprobe_status = KPROBE_HIT_SSDONE;
- p->post_handler(p, regs, 0);
- }
- __this_cpu_write(current_kprobe, NULL);
+ if (!p->pre_handler || !p->pre_handler(p, regs))
+ skip_singlestep(p, regs, kcb);
+ /*
+ * If pre_handler returns !0, it sets regs->ip and
+ * resets current kprobe.
+ */
}
end:
local_irq_restore(flags);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 35b4315d84f5..098f396aa409 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1418,9 +1418,6 @@ static __kprobes int check_kprobe_address_safe(struct kprobe *p,
/* Given address is not on the instruction boundary */
if ((unsigned long)p->addr != ftrace_addr)
return -EILSEQ;
- /* break_handler (jprobe) can not work with ftrace */
- if (p->break_handler)
- return -EINVAL;
p->flags |= KPROBE_FLAG_FTRACE;
#else /* !KPROBES_CAN_USE_FTRACE */
return -EINVAL;